There is a worm in the Natural History Museum, in London, that is 200 years old. As well as being historically valuable, it is key to Dr Gordon Paterson's research. A zoology researcher and polychaete worm specialist, he often refers to the museum's collection of pickled polychaetes and extensive library of worm descriptions, some dating back to 1850. This was the hidden side of the museum, with just 1% of the collection on display. But now 22 million specimens preserved in spirits, ranging from microscopic plankton to a two and a half metre swordfish, can be viewed in the purpose-built Darwin Centre.

It is a unique venture, for animals in alcohol are not the only creatures on display - the scientists will be, too. We can now watch such researchers as Paterson in the lab, and hear talks, held twice a day, about their studies. "We want to get across to the public how interesting and relevant our work is," says Paterson. "We want people to know we're collaborating internationally on issues that are relevant to people."

Paterson describes his work as the "cutting edge of biodiversity research". The worms he studies are unassuming - less than 10cm in length - but there are 20,000 known species, and at least that many as yet unnamed. Seventy per cent of the organisms at the bottom of the sea are polychaete worms. "The deep sea is the last unexplored frontier. Half of the planet exists below a kilometre of water," says Paterson.

Paterson is following in the footsteps of a tradition established more than a century ago. The Victorians did not realise there was life in the oceans and thought the sea bed was a sheet of ice. "Finding out whether anything lived at the bottom of the sea was as interesting a question for them as finding life on other planets is for us," says Paterson. In 1870, HMS Challenger, led by Wyville Thomson, conducted the first scientific survey of the deep ocean.

Paterson and his colleagues collect specimens in a similar way to Thomson, bringing up core samples of sediment and examining the contents for life. Finding out how many worms live at the bottom of the sea is not merely an academic question. Many governments are interested in mining for manganese, as it is essential to iron and steel production. Nodules the size of cricket balls can be found on the sea floor in areas such as the Clipperton and Clarion Fracture Zone in the east Pacific, north of the equator. Experimental methods of extraction rely on a device that crawls across the seabed sucking up the sediment, which is damaging to life forms. The trawler spews out this sediment as a mud plume that stretches for kilometres and is capable of suffocating marine organisms.

A UN organisation, the International Sea Bed Authority, has asked Paterson to determine what impact manganese mining could have and whether the exploitation can be regulated. "The short answer is that we don't know," says Paterson.

His work on the biodiversity of worms may help. If he finds that worm species are evenly distributed round the site, then mining will not be too detrimental. "Although species will be killed, it may be possible to mine in a sustainable way," he says. However, if species differ widely over the fracture zone, mining will be more problematic.

Surely no one will be concerned by the death of a few worms? Paterson disagrees. Carbon dioxide is locked in the sediment the worms inhabit and we do not know whether worms sequester carbon. "The worms are an integral part of this ecosystem and may play a role in the climate cycle. Destroying them could be catastrophic."

Paterson's first worm-gathering expedition begins in March, as he will explain to the public in December. The opening of the Darwin Centre signals a huge change for the 350 scientists who work in the museum. "We have to be able to give presentations to the public, and it's not something we currently do. We're not used to talking to anyone other than our peers," says Paterson. "To make our work sing will be a challenge."